1978 年 34 巻 12 号 p. T562-T568
When a polyester sliver of 3500tex (50grain/yd) composed of 0.17tex (1.5den)×38mm crimped fibers was being produced by a flat card with cylinder speeds in 45, 100, 150, 200, 300, 400 or 500rpm, instantaneous photographs of fibers on the metallic wires were taken by using a flash gun of 10 microseconds through a specially-installed transparent plastic window in 200mm×100mm, attached on the front stripping door.
In order to analyse the photographs of crimped fibers on the surface of the carding cylinder under the running condition, two kinds of simulation tests, a wind-tunnel test and a load-elongation test of single fibers, were carried out.
From these experiments, we obtained the following conclusions.
(1) Aerodynamic tensile force on a single fiber on the surface of the cylinder is about 1.5 to 3.0mg when the speed of cylinder is 150 to 300rpm. This tensile force is approximately one twentieth of the force to straighten out the crimp of the fiber.
(2) The crimp per cent, i.e. the percentage of the reduced fiber length caused by crimp to the fully straightened fiber, is 17_??_12% under such low cylinder speeds as 45_??_100rpm, suggesting insufficient carding action under these conditions.
(3) The crimp per cent is decreased from 10 to 7 by increasing the cylinder speed from 150rpm to 300rpm, indicating that fibers are carded being almost straightened, and efficient carding action is attained under this speed range of practical use.
(4) Increasing the cylinder speed over 300rpm scarcely improves carding action because of the decreased decrement in the crimp per cent.